Macroinvertebrate Community and Pollution Tolerance Index in Edion and Omodo Rivers in Derived Savannah Wetlands in Southern Nigeria

Abstract

We carried out a study of the macroinvertebrates community and pollution tolerance index (PTI) in Edion and Omodo Rivers in Agbede wetlands for eight months (from March to October, 2010). Two stations, upstream and downstream, were chosen for each river. Benthic fauna was sampled fortnightly, using the modified Ekman Grab designed for shallow waters. Eight major taxonomic groups comprising 33 taxa were collected in this study. The dominant groups by percentage density occurrence were Ephemeroptera (45.4%) > Diptera (24.7%) > Decapoda (24.03%). The number of taxa was least for station 2 (14) and was highest (23) for station 4, with highest population density recorded for station 1 (211 individuals). The heterogeneity indices revealed higher values for evenness across the stations except, for station 1 (0.3574). Meanwhile, PTI values showed moderate water quality with range of values from 7 to 16.

Application of Biotic Indices and Pollution Tolerance Index in Assessing Macro-Invertebrate Assemblage of Ediba River, Cross River State, Nigeria

“…Ephemeroptera and Zygoptera were poorly represented accounting for 0.82% and 1.44% respectively of the relative abundance [6] reported high diversity of Ephemeroptera which includes Ademophleboides sp., Baetis sp., Centroptillum sp., Cloeon sp., Cloeon bellum and Ephemerella ignita in Edion and Omodo Rivers in Southern forceps into different groups and preserved in 4% Formalin. Then, they were identified and counted, using standard keys according to [13][14][15][16].…”

“…Bio-monitoring studies and the use of macro-invertebrates to rate the quality of water bodies of both lotic and lentic types have been widely reviewed elsewhere [5,6]. The use of pollution tolerance index (PTI) as a method of measuring the overall health status of aquatic bodies through the use of macro-invertebrates remains the most reliable and effective method [7][8][9].…”

Pesticides distribution in surface waters and sediments of lotic and lentic ecosystems in Agbede wetlands

“…The features of this locality have been described in detail by Olomukoro and Dirisu, 2014;and Dirisu and Olomukoro, 2015). The region is predominantly agrarian and all forms of human activities like washing, bathing, scattered settlements, fishing, mining of top soils and trading amongst others are observed here.…”

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“…Omodo stream flows in the South-East direction with few tributaries which are seasonal. The climate of Agbede has been previously described (Ikhile & Aderogba, 2011;Olomukoro & Dirisu, 2014). The meteorological data is shown if Figure 2.…”

“…In the last few decades, aquatic ecologists have focused more of their researches on water quality, resources management and sustainable utilization, which have become more challenging with climate change phenomena. Although: inundation, siltation, agriculture, deforestation, industrialization and urbanization were itemized to pose greater challenges to aquatic regimes in recent times (Olomukoro & Dirisu, 2014). Surface water quality is an essential component of the natural environment and a matter of serious concern today (Liu, Yu, & Chung, 2011).…”